The San Francisco Gay Men’s Chorus is singing a particularly challenging 2016 work, “Seven Last Words of the Unarmed,” in its upcoming 40th anniversary season spring concert, “Bridges.”

“It’s the perfect time to challenge our audience with this piece,” says SFGMC Artistic Director Tim Seelig, who leads the choir and special guests in the multi-movement work by Atlanta-based composer-educator Joel Thompson next week at Davies Symphony Hall.

Based on Joseph Haydn’s “Last Seven Words of Christ,” Thompson’s increasingly popular work is built around the final words of seven unarmed black men — including Michael Brown, Oscar Grant and Trayvon Martin — who were killed at the hands of authorities.

“It wasn’t a commission; I wrote it as a way to process my own grief and feelings after the Eric Garner decision, when the grand jury did not indict the officer whose actions led to his death,” says Thompson, referring to the 2014 case in which Garner, whose final uttering was “I can’t breathe,” was stopped by New York police on a Staten Island street and put into a chokehold.

Joel Thompson’s “Seven Last Words of the Unarmed” is on the program of the San Francisco Gay Men’s Chorus’ spring concert. (Courtesy San Francisco Gay Men’s Chorus)

Inspired by artist Shirin Barghi’s #lastwords, a series of pictograms pairing seven victims’ final words with simple illustrations, Thompson says he wrote “Seven Words” during a winter break, in two weeks.

He pulled together a small group to present it at Emory University; one of the singers knew Eugene Rogers, director of the University of Michigan Men’s Glee Club, which premiered it in 2016.

While the composition has led to valuable, necessary conversations about race and brought him attention and as well as commissions for more social justice-themed music, at the same time, he admits, “It’s inherently divisive,” prompting negative reaction that he doesn’t always understand.

That thought is not lost on Seelig, who had access to the music for months (“My initial reaction: That takes more courage than I have,” he says) but did not find the opportunity to program it until now, on the heels of the chorus’ fall 2017 “Lavender Pen” tour.

In the wake of Donald Trump’s election, the group decided to visit Alabama, Mississippi, North Carolina, South Carolina and Tennessee — the states with the worst records on LGBT rights — to make a “grandiose” statement, to work to change laws, as well as support local gay communities.

It was a transformative experience, Seelig says, from marching on the Edmund Pettus Bridge in Selma, Ala. (site of the famed 1965 civil rights march) to appearing, with drag queens and all, in a Southern Baptist church in Greenville, S.C.: “They wanted the whole enchilada.”

Yet, although the chorus donated $100,000 ticket proceeds to local LGBT groups, at the same time, Seelig says, “We witnessed the stark reality of bigotry right before our eyes.

On tour, the chorus — 275 members of diverse ages and backgrounds — was joined by the Oakland Interfaith Gospel Choir, which also appears in “Bridges,” as do singers from the Oakland Interfaith Community Choir and Oakland Interfaith Youth Choir, making for 500 voices.

In addition to sharing songs and video from the tour, the concert also includes “Singing for Our Lives,” a protest tune performed in 1978 by SFGMC at the candlelight vigil after San Francisco Supervisor Harvey Milk and Mayor George Moscone were assassinated.

Its composer, songwriter-activist Holly Near — “whose music, like Thompson’s, comes out of personal expression and a deep need to share,” Seelig says — will join SFGMC at the performance.